"The individual mandate rests on a claim of federal power that is both unprecedented and unbounded: the power to compel individuals to engage in commerce in order to more effectively to regulate commerce," Paul Clement, a lawyer for the states, argues in court papers.
If Congress can compel individuals into the market place, he says, there are no limits to its power. "Given the breadth of the modern conception of commerce, there is almost no decision that Congress could not label 'economic' and thereby compel under the federal government's theory."
Clement says the law is unconstitutional under the Commerce Clause as well as Congress's taxing power. He notes that supporters of the law knew that Congress lacked public support to enact a tax, so it came up with the unprecedented mandate instead.
Clement says there is a reason that the individual mandate is unprecedented: "The only explanation for the utter absence of comparable mandates is the utter absence of constitutional authority to enact them."
2. What happens to the rest of the law if the mandate is struck down?
Does that mean the rest of the law falls as well? The actual legislation is hundreds of pages long and includes provisions having little to do with the mandate.
The government hopes the court will never get to this question. Lawyers for the Obama administration say that if the mandate falls, two popular provisions would also fall, but the rest of the law should survive. The most popular part of the law that would fall is the "guaranteed issue" that, in part, requires health insurance companies to offer and renew coverage even if an individual has a pre-existing condition.
"As Congress' findings recognized, those provisions would create a serious adverse selection problem without a minimum coverage provision, producing higher costs and less insurance. They are therefore inseverable," the government argues.
But at a recent event hosted by Bloomberg Law and Scotusblog, Michael Carvin, a lawyer representing the National Federation of Independent Business and four individuals, said he entire law must fall if the mandate is struck down.
"Once you've ripped the heart and the lung out of the body, it doesn't matter that the fingers continue to actually move, " Carvin said. "What matters is if they can move in the way Congress intended."
The court has appointed a lawyer to argue a third position that was taken by the 11th Circuit Court of Appeals: Even if the mandate falls, every other provision of the law should still stand.
"Although the guaranteed issue and community rating provisions were meant to work together with the minimum coverage provision and likely will operate less ideally without the minimum coverage provision," H. Bartow Farr III, the counsel of record appointed by the court, argues, "it does not follow that Congress, confronted with that prospect, would prefer to return to the prior health insurance system, where large numbers of people, in need of insurance but with pre-existing illnesses or conditions were excluded from the market. "